bow leg

Last reviewed 01/2018

Lateral bowing is not uncommon in infants and is normal in a child less than 2 years old. It can be caused by a growth disturbance of the tibial epiphysis and the tibial shaft.

  • common from birth to the early toddler, often with out-toeing (maximal at approx. 1 year); most resolve by 18 months (1)

Consider and exclude rickets - particularly in individuals with a high phytate intake e.g. chapati eaters and vegetarians.

Measurement of the degree of deformity can be achieved by:

  • getting the patient to stand with both patellae facing forward and then measuring the distance between them
  • radiographic estimation: the angle between the longitudinal axes of both the femur and the tibia

Severe deformation may be amenable to osteotomy.

Notes:

  • anterior bowing is always significant; causes include:
    • congenital absence of the fibula
    • neurofibromatosis type 1
    • osteogenesis imperfecta
  • posterior bowing:
    • is rare
    • looks serious, but usually responds to simple stretching and splinting

Reference:

  • ARC. Sports-Related Musculoskeletal Disorders. Reports on the Rheumatic Diseases 2008;14.